&nbsp\\;running between 2000 -3000 rpms, my bike surges pretty bad. it drives crazy cause cruising( whether in town or on highway) i usually run around 2800 rpms. ive had it dyno tuned with SERT, SE air cleaner, and rinehart true duals&nbsp\\;and it still does it.&nbsp\\; i have heard that its probably a lean surge...is that true? it still runs pretty hot too- front cyl head 305 degrees and rear is 345 degrees. what can i do to cure this?

 

Although the classic lean surge is usually lower in rpm, it sounds like you have a lean condition in that range. It will cool down a lot once that is taken care of. It is definately not tuned.
Ron

 

Take it back to your tuner and make him fix it.

 

Maybe it is an exhaust gas leak.&nbsp\\; Either at the head pipe or where the slip fit mufflers bolt on.

m.a.c.

 

&nbsp\\;i have had it back to the tuner once already. he made some adjustments but it is still doing it. he told me to bring it back again&nbsp\\;if it is still doing it.
&nbsp\\;
an exhaust leak could cause a surge? never heard that before.

 

Assuming everything else is OK like fuel pressure and exhaust leaks... The only way I know of to get that out of a Harley is to kill the o2s.&nbsp\\; This is not really a good compromise as othere issues can show up with the o2s out of the loop.&nbsp\\; You can see it fairly clearly in this log.&nbsp\\; This bike has the o2s connected.
&nbsp\\;
Have the tuner try setting all of the 14.6 AFR cells to 14.5 and see if the hunting disappears.&nbsp\\; Caution: if there are holes in the tune the stock UCU will not be able to help fill in the holes.
&nbsp\\;
Hope this helps
&nbsp\\;

 

[quote]ORIGINAL: whittlebeast

Assuming everything else is OK like fuel pressure and exhaust leaks... The only way I know of to get that out of a Harley is to kill the o2s.&nbsp\\;\\\\\\; This is not really a good compromise as othere issues can show up with the o2s out of the loop.&nbsp\\;\\\\\\; You can see it fairly clearly in this log.&nbsp\\;\\\\\\; This bike has the o2s connected.
&nbsp\\;\\\\\\;
Have the tuner try setting all of the 14.6 AFR cells to 14.5 and see if the hunting disappears.&nbsp\\;\\\\\\; Caution: if there are holes in the tune the stock UCU will not be able to help fill in the holes.
&nbsp\\;\\\\\\;
Hope this helps
&nbsp\\;\\\\\\;
[quote]
&nbsp\\;
ok...i am going to look like a complete idiot here but i have no idea what that log says. or anything else about AFR or SERT.&nbsp\\; i took my bike and SERT&nbsp\\;to my tuner having faith he would know what he was doing. he had been in business a long time and builds some wicked motors.&nbsp\\; after he did the tune i found&nbsp\\; Doc 1 thread about 5 questions to ask your tuner....he didnt answer&nbsp\\; them like it says. his dyno is 15 years old...would that&nbsp\\;make a difference?&nbsp\\; last week i took it back and he made changes 5 times, i took&nbsp\\;test ride&nbsp\\;after each time and it still does it.&nbsp\\;i will check my exhaust tonight but im pretty sure it hass no leaks.&nbsp\\;
&nbsp\\;
will anyone with 07 bike and same set up as i have (see below) bewilling to let me see their&nbsp\\; mapp?&nbsp\\; i really want to get this staightened out cause the surging drives me nuts.
&nbsp\\;
thanks for your help.

 

&nbsp\\;
Would you go to an engine builder that does not use a torque wrench because he is not willing to learn to use one.&nbsp\\; At some point, you or your engine builder will have to break down and be willing to learn to use the tools of the trade.&nbsp\\; EFI is the same thing.&nbsp\\; EFI tuning is having the software to read the hardware.&nbsp\\; Dyno tuning is just one of the more important tools of the EFI tuning trade.&nbsp\\; Reading data logs is the second piece of the puzzle.&nbsp\\; Without the data logs, you (or the tuner) will never get to the finer points of EFI tuning.&nbsp\\; Making&nbsp\\;HP is the easy part.&nbsp\\; Seamless driveability is what takes a "tuner" and is almost impossible on a dyno.&nbsp\\; Acceleration enrichment tuning and the o2 feedback control is everything in driveability.&nbsp\\; The AFR has to remain dead stable under all conditions with a steady and smooth transition as the power requirments change.&nbsp\\; The devel is in the details.&nbsp\\; Many tuners have no idea how to even&nbsp\\;locate the devel, let alone how to deal with it.
&nbsp\\;
If you ever get a chance to drive a new Honda car with one of these $600 OBD2 readers that you can see the wideband AFR, you will not believe what is possible to achieve.&nbsp\\; Perfection is the goal and the obsession.&nbsp\\; EFI tuning is not for the faint of heart.
&nbsp\\;
AW

 

Whittle, I fired off an e-mail reply to your e-mail a little while ago. My MTA logs show your MTA received and queued it for delivery at 2247 EDT this date. Be aware that it might end up in your spam folder since I run my own MTA.

I remember who you are now, with those charts. Let me take a minute to let you know that for that type of image, it is best if it never sees JPEG compression. If you cannot save it initially as a PNG, then save it as a BMP and convert it from that to PNG. Not only will the image (byte) size be less, but it will contain no JPEG artifacts which horrendously degrade such (bitmap) image types (JPEG is best-suited for photographic-type images) while at the same time increasing (usually) file size.

 

I guess I cannot edit that previous post in this forum...

[JD has a slight advantage over me just now]

Here is the rest of what I had intended to say:

Anyway, that information aside, I agree with what I hear you saying in your text. The proof you provide with the screenshot can very easily be taken to mean anywhere from nothing to everything. Like I too can be prone to do, I think maybe you are inferring the recipient will get as much out of so terse amount of information as you do, knowing (yourself) beforehand what it is you were looking for with your chosen elements and their graphic scales.